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PLANT FAMILY: Costaceae
BOTANICAL NAME: Costus ligularis
FORMAL SCIENTIFIC NAME: Costus ligularis Baker
SYNONYMS: Costus verschaffeltianus, Costus fimbriatis, Costus mosaicus, Costus ngouniensis,
This African species is recognized in Paul Maas' monograph on African Costaceae, published on 16 December 2016. (Monograph of African Costaceae, H. Maas-van de Kamer, P.J.M. Maas, J.J. Wieringa, C.D. Specht, Blumea 61, 2016: 280 - 318, http://www.ingentaconnect.com/content/nhn/blumea/2016/00000061/00000003/art00010)
NOTE: seePID5198 for the common "mosaicus" form that is usually found in cultivation. I have transferred C. mosaicus in my database to be a form of C. ligularis based on recent determinations by botanists. However in the new Maas monograph, Costus mosaicus is listed as an insufficiently known species.
The African Plant Database lists this species as accepted.
Costus ligularis, Baker - Flora of Tropical Africa, 1898 - describes this species, Leafy stem 4 ft. long, terminal inflo., large ligules oblong, brown, membranous, obtuse, 1-1 1/2 in. long, no leafy tips to bracts. Leaf pattern (C. mosaicus) not mentioned. Distri. Is Lower Guinea, Corisco Bay, by the Muni River, Mann, 1628!
"2. C. ligularis, Baker. Leafy stem 4 ft. long. Leaves Oblanceolate-oblong, acuminate, 6-8 in. long, about 8 in. broad above the.middle,cuneate at the base, moderately firm, glabrous on both sides; petiolescarcely any; ligule oblong, brown, membranous, obtuse, 1 - 1 1/2 in.Long. Flowers many in a sessile globose cluster, terminal on the leafystem; bracts orbicular, 1/4 in. broad. Calyx 1/4 in. long, toothed at thetip. Corolla-lobes above 1 in. long. Lip 2 in. long and broad, pink;process of fertile stamen an inch shorter than the lip.
Lower Guinea. Corisco Bay, by the Muni River, Mann, 1628!"
W3Tropicos - http://mobot.mobot.org/W3T/Search/pick.html - Author(s): ORSTOM Date: 1988 Publication: List of Vascular Plants of Gabon with Synonymy lists syn. As Costus fimbriatis and Costus ngouniensis
Fairchild Tropical Gardens has this name on the plant that is also sometimes identified as Costus mosaicus or as Costus verschaffeltianus.
Described by Koechlin in Flore du Gabon. Koechlin says he has grouped together "un certain nombre" of plans which are variable in height, form, pilosity, etc, but not enough to merit separate species distinction. Affinities to C. ligularis are C. nudicaulis and C. fissiligulatus. Additional study of living material is necessary to determine the divisions in this group. He does not mention anywhere the distinctive "mosaic" pattern in the leaves, seen in the plant named at Kew as Costus mosaicus, which fits in well with his identification key.